Cathay (; Chinese: 契丹) is a historical name for China that was used in Europe. During the early modern period, the term Cathay initially evolved as a term referring to what is now Northern China, completely separate and distinct from China, which was a reference to southern China. As knowledge of East Asia increased, Cathay came to be seen as the same polity as China as a whole. The term Cathay became a poetic name for China.

The name Cathay originates from the word Khitan, a name of a para-Mongolic nomadic people who ruled the Liao dynasty in northern China from 916 to 1125, and who later migrated west after they were overthrown by the Jin dynasty to form the Qara Khitai (Western Liao dynasty) for another century thereafter. Originally, this name was the name applied by Central and Western Asians and Europeans to northern China; the name was also used in Marco Polo's book on his travels in Yuan dynasty China (he referred to southern China as Mangi). Odoric of Pordenone (d. 1331) also writes about Cathay and the Khan in his travelbooks from his journey before 1331, perhaps 1321–1330.